Activity 1:  Finding p

Parts of a Circle
 

The radius of a circle is half thedistance across or the distance from the center to edge of the circle.	The diameter of a circle is the distance across the circle through the center.

 
The circumference of a circle is the distance around the circle.
 
The Ratio of Circumference to Diameter (p)
Regardless of the size of the circle you consider, you should get about 3.1 when you divide the circumference by the diameter.  This number is called pi and is commonly referred to by the symbol p.  Recall from previous mathematics classes that c = pd and c = 2 pr, where c is the circumference, d is the diameter, and r is the radius of a circle.